added benchHash_avx512 target

tests/bench/.gitignore

diff --git a/tests/bench/.gitignore b/tests/bench/.gitignore
index ede2d58..93f3e07 100644
--- a/tests/bench/.gitignore
+++ b/tests/bench/.gitignore
@@ -4,6 +4,7 @@
 benchHash
 benchHash32
 benchHash_avx2
+benchHash_avx512
 benchHash_hw
 
 # test files

tests/bench/Makefile

diff --git a/tests/bench/Makefile b/tests/bench/Makefile
index 4eb7467..a7edd48 100644
--- a/tests/bench/Makefile
+++ b/tests/bench/Makefile
@@ -49,11 +49,14 @@
 benchHash_avx2: CFLAGS   += -mavx2
 benchHash_avx2: CXXFLAGS += -mavx2
 
+benchHash_avx512: CFLAGS   += -mavx512f
+benchHash_avx512: CXXFLAGS += -mavx512f
+
 benchHash_hw: CPPFLAGS += -DHARDWARE_SUPPORT
 benchHash_hw: CFLAGS   += -mavx2 -maes
 benchHash_hw: CXXFLAGS += -mavx2 -mpclmul -std=c++14
 
-benchHash benchHash32 benchHash_avx2 benchHash_nosimd benchHash_hw: $(OBJ_LIST)
+benchHash benchHash32 benchHash_avx2 benchHash_avx512 benchHash_nosimd benchHash_hw: $(OBJ_LIST)
 	$(CXX) $(CPPFLAGS) $(CXXFLAGS) $^ $(LDFLAGS) -o $@
 
 
@@ -65,4 +68,4 @@
 
 
 clean:
-	$(RM) *.o benchHash benchHash32 benchHash_avx2 benchHash_hw
+	$(RM) *.o benchHash benchHash32 benchHash_avx2 benchHash_avx512 benchHash_hw